I have a very simple code that draws an image on a bitmap, the image must be drawn in the lower right corner. I use TranslateTransform to move the image. This works fine when run under Windows, however, TranslateTransform has no effect when run in Mono under Linux.
byte[] imageBytes = File.ReadAllBytes(#"/home/alexey/Downloads/test.png");
using (Bitmap bmp = new Bitmap(500, 500))
{
using (Graphics gr = Graphics.FromImage(bmp))
{
ImageAttributes attr = null;
using (Image image = Image.FromStream(new MemoryStream(imageBytes)))
{
GraphicsUnit srcGU = GraphicsUnit.Pixel;
RectangleF srcRect = image.GetBounds(ref srcGU);
RectangleF bounds = new RectangleF(0, 0, 100, 100);
// Destination points specify the bounding parallelogram.
PointF[] dstPoints = new PointF[]
{ bounds.Location,
new PointF(bounds.X + bounds.Width, bounds.Y),
new PointF(bounds.X, bounds.Y + bounds.Height) };
// Image must be in the in the lower right corner and it is if run the code under Windows.
// But is run code under linux, the image is in the upper left corner.
gr.TranslateTransform(400,400);
gr.DrawImage(image, dstPoints, srcRect, srcGU, attr);
}
}
bmp.Save(#"/home/alexey/Downloads/out.png", ImageFormat.Png);
}
Of course, the code is a simplified version of the real code that must work in both windows and Linux environments. I narrowed down the code and found that the problems under linux occur because Graphics.Transform has no effect in Mono under linux. Any ideas?
I think the easiest solution would be to simply add 400 to the X and Y components of your dstPoints.
Related
There are a number of questions and answers about setting wallpapers programmatically on multi-monitor setups in Windows, but I'm asking specifically for Windows 10 (and maybe Windows 8) because it seems to work differently from all the explanations I found.
Raymond Chen has an article "How do I put a different wallpaper on each monitor?" (https://devblogs.microsoft.com/oldnewthing/?p=25003), also quoted in Monitors position on Windows wallpaper. The core concepts is that Windows places the top-left corner of the provided bitmap at the top-left corner of the primary monitor, and wraps around to fill any desktop space to the left and/or above that. I understand that, I wrote a little program using that knowledge, and it works beautifully in Windows 7.
How it works: I create a bitmap that conceptually covers the whole desktop space, as the user sees it. I draw the contents of each monitor to that bitmap in its appropriate position (the program is written in C++ using VCL, but the principle remains the same in other programming environments):
TRect GetMonitorRect_WallpaperCoords(int MonitorNum)
{
Forms::TMonitor *PrimaryMonitor = Screen->Monitors[0];
Forms::TMonitor *Monitor = Screen->Monitors[MonitorNum];
// Get the rectangle in desktop coordinates
TRect Rect(Monitor->Left, Monitor->Top, Monitor->Left + Monitor->Width, Monitor->Top + Monitor->Height);
// Convert to wallpaper coordinates
Rect.Left += PrimaryMonitor->Left - Screen->DesktopLeft;
Rect.Top += PrimaryMonitor->Top - Screen->DesktopTop;
Rect.Right += PrimaryMonitor->Left - Screen->DesktopLeft;
Rect.Bottom += PrimaryMonitor->Top - Screen->DesktopTop;
return Rect;
}
std::unique_ptr<Graphics::TBitmap> CreateWallpaperBitmap_WallpaperCoords()
{
std::unique_ptr<Graphics::TBitmap> Bmp(new Graphics::TBitmap);
Bmp->PixelFormat = pf24bit;
Bmp->Width = Screen->DesktopWidth;
Bmp->Height = Screen->DesktopHeight;
// Draw background (not that we really need it: it will never be visible)
Bmp->Canvas->Brush->Style = bsSolid;
Bmp->Canvas->Brush->Color = clBlack;
Bmp->Canvas->FillRect(TRect(0, 0, Bmp->Width, Bmp->Height));
for (int MonitorNum = 0; MonitorNum < Screen->MonitorCount; ++MonitorNum)
{
TDrawContext DC(Bmp->Canvas, GetMonitorRect_WallpaperCoords(MonitorNum));
DrawMonitor(DC);
}
return Bmp;
}
(The draw context uses a coordinate translation rect so that the code int DrawMonitor function can draw in a rectangle like (0, 0, 1920, 1080) without having to wonder where in the full bitmap it is drawing, and with a clip rect so that DrawMonitor can not accidentally draw outside of the monitor it's drawing on).
Then I convert that bitmap to an image that will properly wrap around when placed at the top-left corner of the primary monitor (as Raymond Chen describes in his article):
std::unique_ptr<Graphics::TBitmap> ConvertWallpaperToDesktopCoords(std::unique_ptr<Graphics::TBitmap> &Bmp_WallpaperCoords)
{
std::unique_ptr<Graphics::TBitmap> Bmp_DesktopCoords(new Graphics::TBitmap);
Bmp_DesktopCoords->PixelFormat = Bmp_WallpaperCoords->PixelFormat;
Bmp_DesktopCoords->Width = Bmp_WallpaperCoords->Width;
Bmp_DesktopCoords->Height = Bmp_WallpaperCoords->Height;
// Draw Bmp_WallpaperCoords to Bmp_DesktopCoords at four different places to account for all
// possible ways Windows wraps the wallpaper around the left and bottom edges of the desktop
// space
Bmp_DesktopCoords->Canvas->Draw(Screen->DesktopLeft, Screen->DesktopTop, Bmp_WallpaperCoords.get());
Bmp_DesktopCoords->Canvas->Draw(Screen->DesktopLeft + Screen->DesktopWidth, Screen->DesktopTop, Bmp_WallpaperCoords.get());
Bmp_DesktopCoords->Canvas->Draw(Screen->DesktopLeft, Screen->DesktopTop + Screen->DesktopHeight, Bmp_WallpaperCoords.get());
Bmp_DesktopCoords->Canvas->Draw(Screen->DesktopLeft + Screen->DesktopWidth, Screen->DesktopTop + Screen->DesktopHeight, Bmp_WallpaperCoords.get());
return Bmp_DesktopCoords;
}
Then I install that bitmap as a wallpaper by writing the appropriate values in the registry and calling SystemParametersInfo with SPI_SETDESKWALLPAPER:
void InstallWallpaper(const String &Fn)
{
// Install wallpaper:
// There are 3 name/data pairs that have an effect on the desktop wallpaper, all under HKCU\Control Panel\Desktop:
// - Wallpaper (REG_SZ): file path and name of wallpaper
// - WallpaperStyle (REG_SZ):
// . 0: Centered
// . 1: Tiled
// . 2: Stretched
// - TileWallpaper (REG_SZ):
// . 0: Don't tile
// . 1: Tile
// We don't use the Wallpaper value itself; instead we use SystemParametersInfo to set the wallpaper.
// The file name needs to be absolute!
assert(Ioutils::TPath::IsPathRooted(Fn));
std::unique_ptr<TRegistry> Reg(new TRegistry);
Reg->RootKey = HKEY_CURRENT_USER;
if (Reg->OpenKey(L"Control Panel\\Desktop", false))
{
Reg->WriteString(L"WallpaperStyle", L"1");
Reg->WriteString(L"TileWallpaper", L"1");
Reg->CloseKey();
}
SystemParametersInfoW(SPI_SETDESKWALLPAPER, 1, Fn.c_str(), SPIF_UPDATEINIFILE | SPIF_SENDCHANGE);
}
But when I test it in Windows 10, it doesn't work properly anymore: Windows 10 puts the wallpaper completely in the wrong place. Seeing as other people have asked questions about multi-monitor wallpapers in the past, I'm hoping there are people with experience of it on Windows 10.
As far as I can see, Windows 10 places the top-left corner of the provided bitmap at the top-left corner of the desktop space (by which I mean the bounding rectangle of all monitors), instead of the top-left corner of the primary monitor. In code, that means: I leave out the ConvertWallpaperToDesktopCoords step, and then it works fine as far as I can see.
But I can't find any documentation on this, so I don't know if this is officially explanation of how Windows 10 does it. Use with care. Also I don't know when this different behavior started: in Windows 10, or maybe earlier in Windows 8.
this.canvas = new Canvas(shell, SWT.NO_BACKGROUND);
I'm using a PaintListener:
this.canvas.addPaintListener(new PaintListener() {
#Override
public void paintControl(PaintEvent e) {
// Draw images
synchronized (imageMarks) {
for (ImageMark mark : Whiteboard.this.imageMarks)
{
Image image = Whiteboard.this.getImage(mark.id);
Point position = ScaledPoint.toSWTPoint(Whiteboard.this.getCanvasSize(), mark.getPosition());
Point bounds = mark.getUnscaledBoundaries(Whiteboard.this.getCanvasSize());
e.gc.drawImage(image, 0, 0, image.getBounds().width, image.getBounds().height, position.x, position.y,
bounds.x, bounds.y);
}
}
// Draw pencil marks
synchronized (pencilMarks) {
e.gc.setLineWidth(LINE_WIDTH);
for (double[] line : Whiteboard.this.pencilMarks)
{
Point lastPosPoint = ScaledPoint.toSWTPoint(Whiteboard.this.getCanvasSize(), new ScaledPoint(line[0], line[2]));
Point newPosPoint = ScaledPoint.toSWTPoint(Whiteboard.this.getCanvasSize(), new ScaledPoint(line[1], line[3]));
e.gc.drawLine(lastPosPoint.x, lastPosPoint.y, newPosPoint.x, newPosPoint.y);
}
}
// Draw pointer, assuming it's there
if (pointerMark != null)
{
synchronized (pointerMark) {
Point pos = ScaledPoint.toSWTPoint(Whiteboard.this.getCanvasSize(), pointerMark.getPosition());
if (pointerMark.isFlipped())
e.gc.drawImage(Whiteboard.pointerImageFlipped, pos.x, pos.y);
else
e.gc.drawImage(Whiteboard.pointerImage, pos.x, pos.y);
}
}
}
});
and redrawing the canvas via a canvas.redraw() call. On 64-bit Linux, this seems to be working without any issues, but strangely enough, on 64-bit Windows, nothing ever ends up being erased or redrawn. For example, if the screen is resized, the pencil markings do not resize as well, they just end up being cut out of the screen. When new marks are added (in other words, when the paint listener is called again), the repositioned markings are redrawn on top of the old ones which didn't scale with the window. In other words, I believe the canvas is not being cleared upon canvas.redraw(). Is there a workaround for this?
You are specifying SWT.NO_BACKGROUND which stops the Canvas being cleared before each paint.
If you use SWT.NO_BACKGROUND it is your paint method's responsibility to draw every pixel of the Canvas.
SWT.NO_BACKGROUND JavaDoc:
By default, before a widget paints, the client area is filled with the
current background. When this style is specified, the background is
not filled, and the application is responsible for filling every pixel
of the client area. This style might be used as an alternative to
"double-buffering" in order to reduce flicker. This style does not
mean "transparent" - widgets that are obscured will not draw through.
I have prepared a screen in which I am allowing user to create an account. as shown in the first image I have used an image(bg_BB.png image) as MainScreen Background, after that i have taken another VFM and painting that white Background (white_bg2.png)on that vertical field manager and ADDING ALL MY FIELD ON THAT VFM.
But the problem arises when the keyboard is pops-up. All the fields apears to be floating over the background as shown in the second pic.
Below is the code which I am using:
Bitmap backGroundImage = Bitmap.getBitmapResource("bg_BB.png");
((VerticalFieldManager) getMainManager()).setBackground(BackgroundFactory.createBitmapBackground(backGroundImage));
final Bitmap tabBackGroundImage = Bitmap.getBitmapResource("white_bg2.png");
_mainVfm = new VerticalFieldManager(Field.USE_ALL_WIDTH) {
protected void paint(Graphics graphics) {
int y = CreateUserAccountScreen.this.getMainManager().getVerticalScroll();
graphics.drawBitmap(0, y,
tabBackGroundImage.getWidth(),
tabBackGroundImage.getHeight(),
tabBackGroundImage,
0, 0 );
super.paint( graphics );
}
};
replace your code with:
Bitmap tabBackGroundImage = Bitmap.getBitmapResource("white_bg2.png");
VerticalFieldManager _mainVfm = new VerticalFieldManager(Manager.VERTICAL_SCROLL |
Manager.VERTICAL_SCROLLBAR|
Manager.USE_ALL_WIDTH);
_mainVfm.setBorder( BorderFactory.createBitmapBorder(
new XYEdges(12,12,12,12), tabBackGroundImage
)
);
make sure that your border image have white background.
i use this method and it works perfectly.
In an iPhone app, I wrote some code to resize an image taken from the photo album, in order to use it as background for the app.
The code is strongly inspired from what I could find looking on the net. Namely here:
http://forrst.com/posts/UIImage_simple_resize_and_crop_image-sUG#comment-land
It works fine on the simulator. But it looks like no resizing at all is happening on the device. Why is that? Any idea?
Thank you for any tip.
hi Michel.
i dont know more about your code but i am using this code you can try
this you will find your solution.
here you need to pass image and the required width and height for
that image in this function and you will get another image with that
new size.
-(UIImage *)resizeImage:(UIImage *)image3 width:(int)width height:(int)height {
CGImageRef imageRef = [image3 CGImage];
CGImageAlphaInfo alphaInfo = CGImageGetAlphaInfo(imageRef);
//if (alphaInfo == kCGImageAlphaNone)
alphaInfo = kCGImageAlphaNoneSkipLast;
CGContextRef bitmap = CGBitmapContextCreate(NULL, width, height, CGImageGetBitsPerComponent(imageRef), 4 * width, CGImageGetColorSpace(imageRef), alphaInfo);
CGContextDrawImage(bitmap, CGRectMake(0, 0, width, height), imageRef);
CGImageRef ref = CGBitmapContextCreateImage(bitmap);
UIImage *result = [UIImage imageWithCGImage:ref];
CGContextRelease(bitmap);
CGImageRelease(ref);
return result;
}
I am trying to put in an icon (a scaled image) as part of a button that also contains some text. I am programming in J2ME for the Nokia SDK (S60 device) and using Eclipse.
The code is as follows:
but = new Button("Some text");
Image img = null;
try {
img = Image.createImage("/flower.png");
} catch(IOException e) {
e1.printStackTrace();
}
but.setIcon(img);
The above lines are the code that works properly. I am facing problems in scaling the image to the size of the button. Whenever I try to do that, I get a divide by zero error. The function I am using to scale the image and the way it is being scaled is:
Image img2 = null;
img2 = img.scaled(but.getWidth()/2, but.getHeight());
but.setIcon(img2);
I am unable to figure out why I get a divide by zero error every time I try to run the above code. Is there some other function that I should use? Or is there something I am missing ?
which UI Framework are using, is it LWUIT? if yes, you can't get the width/height of any component before showing the form, you should use getPreferredWidth instead